1. Field of the Invention
The present invention relates to an image forming apparatus that includes an image scanning device.
2. Description of the Related Art
In image scanning devices that are included in copiers, scanners, and printers, or that are included in multifunction products (MFPs) having these functions, i.e., copying, scanning and printing functions, when an abnormality occurs in any one of the above-described devices, a typical method to cope with the abnormality is performed such that a portion or a cause of the abnormality is displayed on that device or terminals that are connected to a network are notified of the abnormality. Japanese Patent No. 3849905 and Japanese Patent Application Laid-open No. 2004-343621 disclose a technology for notifying the existence of an abnormality when a control unit, which controls a device, recognizes the status of a device and detects an abnormality.
The problem is that in the technology disclosed in Japanese Patent No. 3849905 and Japanese Patent Application Laid-open No. 2004-343621, accurate detection of the abnormality cannot be performed. In the image scanning device, because a scanning signal (i.e., a signal used by the device to determine a processing period in which the image processing using scanned image data is performed) that is created by the image scanning device is not monitored, there is a case in which an abnormality cannot be detected even when the scanning signal is abnormal. When the image scanning device cannot detect an abnormal state in which a scanning signal is not created or not output, an image processing unit that processes the scanned image data cannot start image processing, and therefore the image processing unit is kept waiting for an instruction to start image processing, which is a problem with conventional technology.